Electronic systems, such as computer systems, stereo systems, and video systems, may be mounted in rack structures. These rack structures enable the computer or other electronic component to be mounted vertically, preseving floor space. Individual components are mounted in a rack structure using slides that attach to the rack. The individual components can then be slid into and out of the rack. In this manner, the individual components can be accessed for repairing the unit, providing upgrades, configuring the unit, connecting the unit to other components, and other tasks.
The components of a computer system that are often included in a rack system are servers, other computers, and direct access storage devices such as disk drives and RAID subsystems. Other components of rack-mounted electronic systems include amplifiers, CD players, DVD players, radio tuners, VCRs, and televisions. Access to components is provided by the slideable structure attached to the internal frame portion of the rack structure. In this way, components can be moved to a forwardly extended position for servicing. When not being serviced, the component is moved to a rearwardly retracted operating position.
Each component of such a system generally includes cables that attach the component to power sources, communication networks, and other components. Each component generally includes at least one power cable that provides power to the component's power supply. Each component may also have cables connecting the unit with other components both inside and outside the rack. As an example, a rack-mounted computer system component may be coupled to a video monitor so that an operator may monitor the operation of the component or computer system. The component may also be coupled to a printer, a network adapter, a modem, and an external storage device, such as a disk drive, a RAID subsystem, optical disks, or a tape drive. Each of these connections often involves attaching a cable to the component These cabled connections are usually made at the back of the unit by connecting the cable to connectors provided on interface cards installed in the computer or to connectors provided on the back of the individual component. Components may also have communication cables that are connected to other components or to a communication port or outlet outside of the rack structure.
The large number of cables or wires coupled to each component and the large number of cables or wires within each rack may make it more difficult to move components within the rack. The components can often move or slide between a forwardly extended position and a rearwardly retracted position. The cables often include some slack so that the components can be slid to a forwardly extended position without causing the cables to snag or become disconnected. When a component is moved to a rearwardly retracted position, the excess or slack in the cable must be managed so that it does not become entangled with cables attached to other components that are above and below the particular component in the rearwardly retracted position.
Computers and other electronic components that are installed in a rack structure generate heat and must be cooled or must be prevented from overheating in order to ensure the proper operation of each component. Rack-mounted systems are typically cooled using the ambient room air. Ventilation is provided by air passing through the individual components, typically from the rear of the component to the front of the component. As such, it is desirable to organize the cables of a rack-mounted system to allow air flow through the individual components of the rack-mounted system to prevent overheating of a component. As computer and electronic components and systems become slimmer and more compact, the cables servicing the components must be organized in a manner that constrains the cables into a small volume while still allowing sufficient air flow to ventilate the system.
Rack hardware may include an extendable cable arm that is attached to the chassis of the slideable component at one end and attached to the rack on the opposite end. Cable arm assemblies mounted within the rack structure, such as the ones described in U.S. Pat. No. 6,070,742, incorporated herein by reference in its entirety, provide a framework to supply cables to a particular component. Typically, a cable arm servicing a component comprises several segments that are interconnected. A structure of this sort allows the cable arm to extend with the component as the component is extended into the forwardly servicing position and allows the cable arm to fold or collapse to accommodate the component when the component is moved to a rearwardly retracted operating position.
Techniques for supplying cables to a component via a cable arm assembly include fastening a bundle of cables to the cable arm assembly, using straps, such as VELCRO.TM. straps, or cable ties, such as those described in U.S. Pat. No. 5,131,613 and U.S. Pat. No. 4,805,856, each of which is incorporated herein by reference in its entirety. A drawback of these techniques is that the bundle of cables could substantially block the flow of ventilating air to the rack-mounted component. Another drawback of these techniques is that the cables may readily slide through the fastening devices. Thus, because of the force exerted on the cable when the cable arm is extended or retracted, the cable may not be controlled by the fastening devices. Because the cable is not controlled, there is the possibility of damage to the cable or component in the vicinity of the interface between the cable and the component or in the vicinity of the interface between the cable and a connection port Additionally, because the cables may slide, cables may accumulate when the cable arm assembly is in the retracted position, which may cause the cables to become entangled, to snag, or to become disconnected from the component when the cable is extended. Additionally, the accumulation of excess cables behind the component may cause further blockage of the flow of ventilating air. Furthermore, these techniques make it difficult to readily identify, remove, replace, or add a particular cable without the need to remove the component or all of the cables servicing the various components of the rack-mounted system.
Alternatively, cable arm assemblies may include hooks or ports that are integral or are attached to the cable arm. These hooks or ports support the cables supplied to a particular component These techniques include those described in U.S. Pat. No. 4,353,518 and U.S. Pat. No. 5,093,887, each of which is incorporated by reference in its entirety. The drawback of these techniques is that they do not permit a large number of cables to exist in a small area. As computer and electronic systems become slimmer and more compact, it is desirable to organize the cables and wires servicing the components of these system so that the servicing cables and wires use less vertical and horizontal space.
Other cable fasteners and devices for holding cables, such as clamps and hooks, may not provide an adequate system for organizing the cables in a dense configuration in a substantially flat, rectangular, cross-sectional area. Existing techniques may not provide the flexibility to position the cables in one of several positions. As such, the force exerted on the cable when the cable arm is extended or retracted may not be limited by the retaining devices in a manner that reduces the possibility of damage to the cable or component in the vicinity of the interface between the cable and the component or in the vicinity of the interface between the cable and a connection port. Additionally, because cables may readily slide, cables may accumulate when the cable arm assembly is in the retracted position, causing the cables to become entangled, to snag, or to become disconnected from the component when the cable is extended.